Enhanced electrocatalytic hydrogen evolution reaction, oxygen evolution reaction and biomass oxidation over Ce-doped NiPxvia optimization of electronic modulation

Abstract

Electrocatalytic oxidation of 5-hydroxymethylfurfural (HMFOR) to 2,5-furandicarboxylic acid (FDCA) using highly efficient electrocatalysts is currently a research hotspot. In this study, nickel foam-supported Ce-doped transition metal phosphide (i.e., Ce-NiP_x/NF) was synthesized using a one-step electrochemical deposition method. The Lewis acidity of the Ce species offered adsorption sites for oxygen-containing substrates, and the electronic structure of Ni could be effectively adjusted due to its variable valence state. In addition, the charge modulation of Ce and P promoted the rapid valorization of Ni, and the escape of P during the reaction formed many oxygen vacancies, which facilitated the adsorption of HMF. The hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) required overpotentials of only 116 mV and 276 mV for a current density of 10 mA cm⁻², respectively. For HMFOR, the HMF conversion reached almost 100%, and the FDCA yield and Faraday efficiency were 98.69% and 98.38% at 1.40 V_RHE, respectively, and both remained above 95% after 20 cycles. This study presents a facile method for constructing heteroatomic electrodes for electrocatalytic oxidation and reduction and provides a method for designing high-performance electrocatalysts.